Dispenser heads presently in use for dispensing a substance, e.g. generating aerosol sprays for cosmetic purposes in particular, are usually made out of a plastics material such as polypropylene and generally comprise a fixed body secured to the receptacle, the receptacle being fitted with a valve and with a movable pushbutton for actuating the control rod of the valve.
When the user presses down the pushbutton, the substance contained in the receptacle is dispensed via one or more nozzles secured to the pushbutton, generally in the form of a cloud of fine droplets.
Very many improvements have been made to dispenser heads in order to simplify manufacture and/or improve the properties of the aerosol spray delivered.
Nevertheless, so far as the Applicant company is aware, no such improvement relates to the noise made by the dispenser head in operation.
An object of the present invention is to make the operating noise of the dispenser head more agreeable for the user.
The invention achieves this by the dispenser head being made at least in part out of a filled plastics material containing a filler whose density is not less than that of the plastics materials, the nature and/or the content of the filler being selected in such a manner as to diminish and/or modify the operating noise of the dispenser head. In a particular embodiment, the filled plastics material contains more than 50% by weight of a filler relative to the total weight of the filled plastics material.
Although proposals have been made in other technical fields, such as the automobile industry, to use filled plastics materials for the purpose of improving the vibrational properties of certain components, the use of a filled plastics material for the purpose of modifying the operating noise of a dispenser head while dispensing a substance, e.g. the noise caused by generating an aerosol spray, has not yet been proposed.
By means of the invention, the operating noise of the dispenser head is attenuated and/or the main peaks in its acoustic spectrum (frequencies that can be heard by humans) is shifted towards frequencies that are more agreeable to the ear.
Preferably, the filler used has density that is at least twice that of the plastics material with which it is mixed, and preferably its density is at least three times that of the plastics material used.
The filler can advantageously be selected from inorganic substances of density greater than or equal to 3 g/cm3, such as, for example, metal oxides, sulfides, hydroxides, sulfates, or phosphates, or a mixture thereof.
As a filler that is used in preferred manner, mention can be made for example of magnetite, hematite, and barium sulfate.
Advantageously, the plastics material used is polypropylene and the filler is constituted by magnetite constituting at least 60% relative to the total weight of the filled plastics material.
Preferably, the filler used is electrically conductive so as to reduce the risks of accumulating static electricity.
The invention also provides a pressurized receptacle fitted with a dispenser head as specified above.